Transmission and controls

ABSTRACT

A transmission having a multiratio gear unit providing five forward speeds established by the engagement of a forward drive clutch and one additional individual speed engaging device for each forward speed and a reverse drive by the engagement of the second and fourth forward speed devices for reverse drive. A manual selector valve for selecting and holding in a first speed drive, selecting a range providing speed and torque demand controlled automatic shifting between four speeds, second to fifth and selecting further lower ranges each preventing normal automatic shifting to the highest speed in the next higher range but permitting shifts to all available higher speeds at higher than normal overrun speeds. For each speed an automatic shift valve controls a relay valve. The relay valves are hydraulically sequentially arranged so each lower speed relay valve when upshifted feeds through the downshifted next higher speed relay valve to feed the motor to engage the next speed ratio drive. The relay valves each have low and high inlet, supply and exhaust ports. In the downshift position the low inlet port is connected to the low supply port and the high supply port is connected to the high exhaust. In the upshift position the high inlet port is connected to the high supply port and the low supply port is connected to low exhaust. The second and higher relay valves have a low inlet port having a restricted feed and a one-way bypass return. Thus each speed drive motor is fed for each speed drive engagement through its restricted feed passage on both up and down shifts and each speed drive motor is exhausted for speed drive disengagement through one restricted exhaust passage on upshifts and another restricted exhaust passage on downshifts to provide individually controlled motor feed and thus engagement rates and individually controlled exhaust rates at one rate during upshift and another rate during downshifts.

United States Patent Schaefer et a1.

[54] TRANSMISSION AND CONTROLS [72] Inventors: Robert H. Schaeter,Westfield, lnd.;

Joseph R. Fox, Waukesha, Wis.

{73] Assignee: General Motors Corporation,

Detroit, Mich.

[221 Filed: April 29, 1971 [21] Appl. No.: 138,655

Related U.S. Application Data [63] Continuation-in-part of Ser. No.852,760, Aug.

25, 1969, abandoned.

[52] US. Cl. ..74/864, 74/645, 74/731, 74/869, 192/329, 192/109 F [51]Int. Cl ..B60lt 21/06, Fl6h 5/48, F16h 47/08 [58] Field of Search..74/864, 869

[56] References Cited UNITED STATES PATENTS 3,025,723 3/1962 Miller..74/D1G. 1

3,078,736 2/1963 Meads et al ..74/752 X 3,255,642 6/1966 Christenson etal. ....74/869 X 3,336,815 8/1967 Leonard ..74/869 X 3,387,508 6/1968Searles et al ..74/864 3,400,612 9/1968 Pierce, Jr ..74/864 3,452,6217/1969 Golan et al. ..74/752 3,505,907 4/1970 Fox et a1 ..74/7533,541,887 11/1970 Van Lent et al. ........74/869 X 3,625,090 12/1971Chana ..74/864 3,656,372 4/1972 Chana ..74/753 Primary ExaminerCarltonR. Croyle Assistant Examiner-Thomas C. Perry Attorney-W. E. Finken andA. M. Heiter 1 51 Sept. 19, 1972 [57] ABSTRACT A transmission having amultiratio gear unit providing five forward speeds established by theengagement of a forward drive clutch and one additional individual speedengaging device for each forward speed and a reverse drive by theengagement of the second and fourth forward speed devices for reversedrive. A manual selector valve for selecting and holding in a firstspeed drive, selecting a range providing speed and torque demandcontrolled automatic shifting between four speeds, second to fifth andselecting further lower ranges each preventing normal automatic shiftingto the highest speed in the next higher range but permitting shifts toall available higher speeds at higher than normal overrun speeds. Foreach speed an automatic shift valve controls a relay valve. The relayvalves are hydraulically sequentially arranged so each lower speed relayvalve when upshifted feeds through the downshifted next higher speedrelay valve to feed the motor to engage the next speed ratio drive. Therelay valves each have low and high inlet, supply and exhaust ports. Inthe downshift position the low inlet port is connected to the low supplyport and the high supply port is connected to the high exhaust. 1n theupshift position the high inlet port is connected to the high supplyport and the low supply port is connected to low exhaust. The second andhigher relay valves have a low inlet port having a restricted feed and aone-way bypass return. Thus each speed drive motor is fe for ea h s eeddrive en a e ent thro h it restr ned fee pas age on both u ng downshiffs and each speed drive motor is exhausted for speed drivedisengagement through one restricted exhaust passage on upshifts andanother restricted exhaust passage on downshifts to provide individuallycontrolled motor feed and thus engagement rates and individuallycontrolled exhaust rates at one rate during upshift and another rateduring downshifts.

36 Claims, 6 Drawing Figures rug PATENTEU EP BR 3.691.872 saw u or 5 zzzEul E 278 if 50L. VAL

(mau DETENT 5; VALVE GOVERNOR VALVE INVENTORS mm A! M6 fiweph R. $0.2:

9- auwu ATTORNEY PATENTEBsEP 19 m2 SHEEI 5 BF 5 r 6 a @M x m m w w m w ofin mvu w a w m m M M 4 m A 2 J 8. H 4 m ww T m a w .0 I. 4 7 6 w 5 m zf L\ d a b m a w m w n. w m w w m w 2 M.) R m P w a P m 8 l m z I H m afl M W LT, I. i a 5 r W NM? w. I fi AT TOR NEY TRANSMISSION AND comorsThis invention relates to an automatic transmission and controlstherefor and is a continuation in part of Applicants prior applicationSer. No. 852,760 filed Aug. 2S, 1969, not abandoned.

This invention is shown in a transmission having a torque converterlockup clutch and five speed gearing drive having a forward input clutchengaged in all forward drives and one individual speed drive engagingdevice sequentially operated for each of the five forward speeds. Thesecond and highest individual speed drive engaging devices are engagedfor reverse drive.

Since this five speed transmission having first to fifth speeds alsoprovides a four speed transmission by using only the second to fifthspeed gearing and controls, these speeds are called the first to fourthspeeds and the first or lowest speed is called low speed in the detaileddescription of the preferred embodiment. The improved controls utilize asimple construction preventing simultaneous engagement of more than oneforward speed drive and providing under proper conditions manualselection of low and reverse drive and several forward drive rangesproviding one speed or groups of speeds under various modes of control.Thus there are various control sequences involving difierent groups ofat least three speeds, a lower, an intermediate and a higher speed, forconvenience referred to as a first, second and third speed. The controlsystem has a manual selector valve actuable in a lowest or manual rangeto select and hold a first speed drive and four higher automatic rangesproviding automatic control in four higher speed drives, second tofiflh.

The highest automatic range provides automatic speed governor and torquedemand shifting at normal vehicle speeds between second and fifth speedsand each consecutively lower automatic range, provides this typeshifting between second and one lower speed when it is desired tonormally hole the transmission in a lower speed drive. When in any lowerautomatic range, though normal automatic shifting to speed drives notincluded in the range is prevented, shifting to and from these speeddrives is permitted at higher than normal vehicle speeds or hold speedsencountered on overrun. A throttle actuated detent control provides forautomatic shifting at a speed, intermediate, normal shift speeds and thehold shift speeds. The automatic shifi valves provide upshifting at anincreasing speed with increasing throttle and downshifting at lowerspeeds increasing at a faster rate than the upshift speeds withincreasing throttle between second and fifth speeds. The shift valve foreach automatic shift change controls a relay valve which functions on anupshift to connect a pressure through the relay valve for the nexthigher speed which is then in the downshift position so that theultimate control for each speed establishing device is controlled by thesame valve element so only one can be established at a time and by itsindividual feed restriction to suit its feed requirements independent ofthe others. Each speed device has independent upshift and downshiftexhaust restrictions independent of the others. The relay valve for thelowest speed in the automatic ranges, first speed, when upshifted feedsthe next higher speed relay valve as pointed out above and only whendownshifted feeds a governor inhibited manually controlled first and lowspeed relay valve controlled by the selector valve to provide a manualshift to low and reverse only at proper speeds.

The feed to the governor controlled lockup clutch valve is exhausted andinterrupted for a timed period after initiation of pressure in any oneline engaging one of the automatically controlled forward speed engagingdevices for a shift by a series of cut-off shuttle valves so the lockupclutch is disengaged during each shift An object of the invention is toprovide in an automatic transmission having a series of increasing speeddevices for establishing a series of speeds and an improved controlproviding a plurality of increasing drive speed signals in accordancewith output speed and torque demand and operating a series of relayvalves sequentially establishing the series of increasing speed devicesand having a continuous feed to a first relay valve for the first speeddrive in the series and a manual selector valve controlled feed for thehigher speed drives in the series feed through the upshifted first relayvalve and the downshified second relay valve for second speed andthrough the upshifted first and second relay valves and the downshiftedthird relay valve for third.

Another object of the invention is to provide in an automatictransmission having a series of individual speed drive devices forestablishing a series of increasing forward speed drives and a lower anda higher of said individual speed drive devices establishing reverse, animproved control providing a plurality of drive speed signals for aseries of increasing speed drives in accordance with output speed andtorque demand and operating a series of relay valves sequentiallyestablishing the series of increasing speed drives and having a firstfeed to the first relay valve which when downshifted establishes a firstspeed drive device and a manual selector valve operative in an automaticrange position to establish the forward drive device to then establishfirst speed and a second feed to the first relay valve which, whenupshifted, feeds through the downshifted second relay valve to a secondspeed device for establishing second speed drive and the second relayvalve when upshifted continuing the second feed through the downshiftedthird relay valve to a third speed device for establishing third speeddrive and the upshified third relay valve to a fourth speed forestablishing fourth speed and the selector valve having a reverse driveposition disestablishing the forward device and discontinuing the secondfeed and supplying the downshifted third relay valve to feed the fourthspeed device and operative when the first relay valve is automaticallydownshifted to feed the first speed device for establishing reversedrive.

Another object of the invention is to provide in an automatictransmission having a series of individual speed drive devices forestablishing a series of increasing speed drives, an improved controlsystem having a series of relay valves including a first relay valvesupplying the first or second speed drive device, a second relay valvesupplying the first or third relay valve and the third relay valvesupplying the third speed device or a fourth speed device, control meansresponsive to output speed and torque demand sequentially shifting saidsecond and third relay valves, a continuous fluid source connected bysaid second relay valve, only when downshifted, to supply said firstrelay valve and a selector valve operative in an automatic shift rangeposition providing a fluid supply connected by said second relay valveonly when automatically upshifted to said third relay valve andoperative in a low speed selecting position to disconnect said fluidsupply and downshift said first relay valve.

Another object of the invention is to provide in an automatictransmission having actuator devices including a forward actuator deviceestablished in all forward speeds and a plurality of individual forwardspeed actuator devices selectively actuated for establishing forwardspeed drives and an improved control system having a manual controloperative in a forward automatic position to effect transmissionshifting through a governor responsive shift control which is operativein response to changes in speed to automatically control shiftingbetween the automatically controlled speed drives and an additionalspeed position operative only when the automatic speed responsive shiftcontrol is in the lowest speed position to effect engagement of anadditional speed drive.

Another object of the invention is to provide in an automatictransmission having a forward actuator device established in all forwardspeeds and a plurality of individual forward speed actuator devicesselectively actuated for establishing the forward speed drives and areverse drive being established by engagement of the lowest and highestindividual forward speed actuating devices and an improved controlsystem having a manual control operative in neutral to engage the lowestspeed actuator device, operative in forward drive to engage the forwardactuator device and condition a speed responsive shift control todisengage the lowest speed actuator device and to engage the next higherspeed actuator device with increasing speed and operative in reverseposition to disengage the forward fluid actuator device and engage theindividual highest speed actuator device to provide reverse drive onlywhen the speed responsive shift control is in the lowest speed position.

Another object of the invention is to provide in an automatictransmission having a forward actuator device established in all forwardspeeds and a plurality of individual forward speed actuator devicesselectively actuated for establishing the forward speed drives and animproved control system having a manual control operative in a forwardautomatic position to effect transmission shifting through a governorresponsive shift control which is operative in response to changes inspeed to automatically control shifting between the second speed driveand higher speed drives and a first speed position operative only whenthe automatic speed responsive shift control is in the second speedposition and the output speed of the transmission is below apredetermined value to effect engagement of the first speed drive.

Another object of the invention is to provide in a transmission having aseries of individual speed drive devices for establishing a consecutiveseries of increasing forward speed drives, an improved control systemhaving shift valving and flow passages having a flow controlling feedpassage portion for each individual speed drive device for controllingthe establishing rate of each speed drive device independently of thecontrolling feed and exhaust passage portion for establishing feed andexhaust rates for the other speed drive devices and independent upshiftexhaust and downshift exhaust flow controlling feed passage portions foreach speed drive device exhausted on an upshift and a downshift so theflow of establishing feed, upshift exhaust and downshift exhaust foreach speed drive device are controllable independent of the other flows.

Another object of the invention is to provide in a transmission having aseries of individual speed drive devices for establishing a series ofincreasing forward speed drives, an improved control system having aseries of shift valves, the first shift valve connecting the source whendownshifted to a first speed device and, when upshifted, to a secondshift valve which, when downshifted, continues the connection to asecond speed device and, when upshifted, to a third speed device andhaving a flow controlling feed passage portion for each individual speeddrive device for con trolling the establishing rate of each speed drivedevice independent of the establishing and exhaust rates for the otherspeed drive devices and independent exhaust flow controlling upshiftexhaust and downshift exhaust passage portions for each speed drivedevice exhausted on an upshift and downshift so the flow of establishingfeed, upshift exhaust and downshift exhaust for each speed drive deviceare controllable independent of the other flows.

Another object of the invention is to provide in a transmission having aseries of individual speed drive devices for establishing a consecutiveseries of increasing speed drives, an improved control system having afirst and a second shift valve each having first and second inlet ports.first and second outlet ports and first and second exhaust ports and thefirst shift valve being operative in a downshift position to connect itsfirst inlet port having a first speed flow control portion to its firstoutlet port and first speed device and connect its second outlet port toits second exhaust port having a downshift flow control portionoperative on a two-one shift and in an upshifi position to connect itssecond inlet port to its second outlet port and its first outlet port toits first exhaust port having an upshift flow control portion operativeon a one-two upshift, the second shift valve in a downshift positionconnecting its first inlet port having a second speed flow controlportion to its first outlet port and the second speed device andconnecting the third speed device by its second outlet port to itssecond exhaust port having a downshift flow control portion operative ona three-two shift and an upshift position connecting said second inletport having a third speed flow control portion to said second outletport and the third speed device and connecting said second speed deviceby its first outlet port to its first exhaust port having a flow controlportion operative on a two-three shift, and the second speed controlportion having a return bypass so its exhaust on a twoone shift iscontrolled by the flow control portion of the first shift valves secondexhaust port.

These and other objects of the invention will be apparent from thefollowing description and drawing of the invention.

FIGS. 2, 3, 4, 5 and 6 when arranged according to FIG. 1 schematicallyshown the gearing and control of the transmission.

Referring to the drawing, FIG. 2 shows the power train having an inputshaft driving a rotary torque converter housing 12 which drives the pump14. The pump hydroltinetically drives the turbine 15 and the fluid isredirected by the stator 16 to the pump 14. The stator is mounted on aone-way brake 17 secured to a sleeve 18 fixed to the housing 19. Theturbine is connected by a hub 21 to the torque converter output shaft22. A lockup clutch 23 for directly connecting the input shaft 10 to theconverter output shaft 22 has a fixed backing plate 24 mounted on therotary housing 12, a driven plate 26 connected through hub 21 to drivethe output shaft 22 and a diaphragm piston and apply plate 27 whichforms a closed expansible chamber 29 between the diaphragm piston 27 andthe front wall of the rotary housing 12. A hydrodynamic brake 30 isprovided by a plurality of vanes 31 mounted for rotation with shaft 22and located in a chamber 32 having fixed vanes 33 formed in thetransmission housing 19.

The four speed gear unit 34 has three planetary gear sets and iscompounded with a low speed gear set 95 to provide 5 speeds which arehereinafter referred to as low and first to fourth. In the four speedunit 34, the rear or first gear set has planetary pinions 36 mounted ona carrier 37 and meshing with sun gear 38 and ring gear 39. The secondgear set has pinions 41 rotatably mounted on carrier 42 and meshing withsun gear 43 and ring gear 44 and the third gear set has planetarypinions 46 mounted on the carrier 47 and meshing with sun gear 48 andring gear 49.

The forward clutch 51 is engaged in all forward ratios and connects theconverter output shaft 22 to drive the range gear unit input shaft 52which drives, through hub 53, the sun gear 38 of the first gear set andthrough hub 54 the ring gear 44 of the second gear set. The forwardclutch 51 has input plates 55 mounted on a drum 56 driven by the rotaryhub 57 drive connected to shaft 22. The hub 57 has a cylinder 58 formedtherein for piston 59. On the supply of fluid by drive four line 203 tothe cylinder 58, the piston 59 engages the input plates 55 and theoutput plates 61 which are connected by a hub 62 to drive the gear unitinput shaft 52. Fourth speed clutch 63 connects the converter outputshaft 22 to the secondary input shaft 64 which drives the sun gears 43and 48 of the second and third gear sets and with the above forwardclutch drive locks the gearing for 1:1 drive from carrier 42, ring gear49 and carrier 37 to the output shaft 99. The fourth speed clutch 63 hasan input drum 66 formed as a continuation of drum 56 and is thus drivenby shaft 22 and drives input plates 67. The output plates 68 areconnected by drum 69 and hub 71 to secondary input shaft 64. The hub 71has a cylinder 72 formed therein for the piston 73 and on the supply offluid to the cylinder by fourth clutch apply line 432, piston 73 engagesthe plates to effect a drive from the converter output shaft 22 to thesecondary input shaft to drive sun gears 43 and 48. The shaft 64 mayalso be held by the third speed brake 76 which has fixed plates 77 androtary plates 78 drive connected through drum 69 and hub 71 to shaft 64to hold shaft 64 and sun gears 43 and 48. When fluid is supplied bythird apply line 436 to the cylinder 79 formed in housing 19 to move thecylinder 81 to engage plates 77 and 78, the brake 76 is engaged to holdthe shaft 64 and the sun gears 43 and 48. The second speed brake 82 hasa plurality of fixed plates 83 fixed to the housing 19 and rotary plates84 connected by hub 83 to the carrier 47 of the third gear set. Whenfluid is supplied by second apply line 419 to the cylinder 86 formed inhousing 19, piston 87 moves to engage the plates 83, 84 and holds thecarrier 47. The first and reverse brake 89 has a plurality of fixedplates 91 secured to housing 19 and rotary plates 93 drive connected toring gear 39. When fluid is supplied, by first speed brake apply line309 to the cylinder 93 formed in housing 19 to move the piston 94 andengage plates 91,92, the ring gear 39 of the first gear set is held.

A low gear set 95 has a plurality of planetary pinions 96 mounted on acarrier 97 and meshing with a sun gear 98 which is drive connected tothe output shaft 99 and with the ring gear 101 which is drive connectedby a hub structure 102 to the ring gear 39 of the first gear set. Thelow brake 103 has a plurality of fixed plates 104 secured to the housing19 and rotary plates 105 secured by drum and hub 106 to the carrier 97.Fluid is supplied by low brake apply line 294 to cylinder 107 in housing19 to move piston 108 to engage plates 104 and 105 to establish lowspeed drive.

CONTROLS The brakes and clutches are engaged as indicated by X on thefollowing chart and the others disengaged to provide neutral, fiveforward speeds and reverse.

Referring to FIG. 6, the fluid exhausted from the control andlubrication system collects in the sump 11 l in the lower portion of thetransmission housing. One pump 112 of a three elements gear pump 114draws fluid through the suction line 116 and delivers fluid to the mainline 117 which passes through the filter 118 and is regulated by themain pressure regulator valve 119. The main pressure regulator valve 119 has a valve element 121 having lands a, b, c, d, of equal diameterand a larger land e located in a stepped bore 122. The valve element 121is biased to the closed position shown by a spring 123 mounted on acombined spring seat and stop element 124 which has a flared end 125providing a seat for the spring and abutting snap ring 126 to retain theseat element and spring in spring chamber vented by exhaust 130'. Themain line 117 has a branch 127 connected between the lands 0 and d andthrough port 128 and the bore 129 through the valve to the port 131between the lands a and b and the port 132 at the end of the valveelements to provide hydraulic bias in chamber 133 opposing the spring toregulate the main line pressure at a predetermined value. Regulatedpressure is supplied by port 132 to the space between the lands a and bto prevent leakage from chamber 133 to the space between lands b and cvented by exhaust 134 to provide a positive seal between the main linepressure at port 128 and chamber 133 for improved regulation. Theforward knockdown pressure line 135 is connected at the step betweenlands d and e to reduce the regulated pressure to i.e. 180 psi in allforward drive positions while pressure in reverse drive is higher, i.e.300 psi. Excess main line pressure in line 117 and chamber 13 moves theregulator valve element 121 to the exhaust position exhausting branch127 to overage line 136 which feeds through restriction 137 to thelubrication line 138 which lubricates the gearing. Overage line 136 isalso connected to the lubrication relief regulator valve 139 which has avalve element 41 biased to a closed position by a spring 142 and isclosed when the overage pressure does not exceed a low value to firstsupply lubrication line 138. When the lubrication pressure issufficient, overage pressure exceeds this intermediate value, i.e. 80psi, and the valve 139 opens to connect overage line 136 to theconverter feed line 146 to supply fluid to the torque converter. Theother pump 147 of the pump unit 114 draws fluid via suction line 148 anddelivers fluid to the converter feed line 146 to provide the main feedto the torque converter. When this torque converter feed pressureexceeds a predetermined low pressure, i.e. 62.5 psi, excess fluid flowsvia branch 151 of converter feed line 146 moving valve element 152against the bias spring 153 of converter bypass valve 150 to exhaustconverter feed pressure to the cooler outlet line 154. The converteroutlet line 156 is connected in FIG. 6 through the cooler 160 to thecooler outlet line 154 where the pressure is limited by the converterpressure regulator valve 157 which has a valve element 158 normallybiased by spring 159 to block passage to exhaust 161 but which, at apredetermined low pressure i.e. 25 psi opens to exhaust 161 to limit thepressure in cooler outlet line 154.

DETENT VALVE A through detent valve 162, FIG. 5, which has a valveelement 163 having equal diameter lands a, b and c located in a bore 164and is biased in an opening direction by a spring 166 located in thespring chamber 167 vented by exhaust 168. Main line pressure 117 isconnected through restricted passage 169 to a chamber 171 to act on theinactivating piston 172 to normally engage valve element 163 and hold itin the extreme right position against the stop element 173 so that thethrough detent valve does not deliver pressure to the detent line 174.When the throttle pedal 176 is at the full throttle position, it closesswitch 1'17 connecting a grounded power source 178 to the solenoid valve179 which opens the port 180 to exhaust 181 to vent fluid in chamber 171to permit the detent valve 162 to regulate pressure. The regulatedpressure supplied from main line 117 via branch 182 to the space betweenlanrk a and b to the branch 183 of detent line 174 and throughrestricted branch 184 to the space between the piston 172 and valveelement 163 to initiate regulation of detent line pressure at apredetermined low value, i.e. 38 psi, determined by spring 166. Excesspressure will move the valve element 163 against the spring 166 andconnect the detent line to exhaust 186.

SELECTOR VALVE The manual selector valve 191 has a valve element 192having equal diameter lands a, b and c. In all valve positions, mainline 117 is connected to the signal feed line 194. In neutral the mainline is also connected to the forward knockdown line 135. The reverseselector line 195 is connected to exhaust 196. The low drive line 197,the drive one line 198, drive two line 199 and the drive three line 201are connected to exhaust 202. The drive four line 203 is connected viahold feed line 204, hold regulator valve 209, hold pressure line 217,drive three line 201 to exhaust 202.

On movement of the selector valve 192 to the reverse position, land 0closes exhaust 196 and opens port 206 to connect main line by fast feedball check valve 207 and slow return restriction 208 to the reverseselector line 195. The forward knockdown line is also exhausted via holdfeed line 204. On movement of the selector valve to drive four position,DR4, reverse is exhausted and in addition to feeding feed line 194 andforward knockdown line 135 as in neutral, the drive four line 203 is fedwhile the other drive lines remain connected to exhaust as in neutral.ln drive three position, DR3, the main line 117 additionally feeds thehold feed line 204 and blocks the exhaust of drive three feed line 201.In drive two position, DR2, the main line feeds the same lines andinterconnects drive two feed line 199 and drive three feed line 201. Indrive one position, DR], the main line feeds the same lines and thedrive one feed line 198, drive two feed line 199 and drive three feedline 201 are interconnected. In low the drive one, two, and three feedlines, 198, 199 and 201, and the low drive feed line 197 are allinterconnected.

HOLD REGULATOR VA LVE The hold regulator valve 209 regulates thepressure distributed by the drive low, one, two, and three feed linesand has a valve element 211 having equal lands a, b and c located in abore 212. A spring 213 located in a spring chamber vented by exhaust 214biased the valve 211 to the open position shown. in the open positionshown, the hold feed line 204 is connected through restriction 216 tothe space between lands b and c and supplies hold pressure supply line217 which is connected to the drive three line 201. This hold pressuresupply line 217 is also connected by restricted passage 218 to theclosed chamber 219. at the end of bore 212 to act on land a of the valveelement to oppose the spring bias. The pressure in chamber 219 moves thevalve against the spring to connect line 217 to exhaust 221 or feed line204 to regulate hold pressure at a valve intermediate main line pressureand detent pressure, i.e. 45 psi.

REAR GOVERNOR The governor valve 223 has a valve element 224 havingequal lands a, b and c mounted in a bore 225 and is rotatably driven bya gear 226 driven from output shaft 99 by a spline connector 227 whichpermits axial movement of the valve element 224 under the influence ofthe rotating governor weights 229 and secondary weights 231 whichprovide a stepped pressure varying with output or vehicle speed. Fluidpressure supplied by the signal feed line 194 through filter 233 isconnected between lands a and b and by a passage 234 through the valveelement to the end valve element 224 to act on the end of the valveelement to move it to an exhausting position connecting governor signalline 236 to exhaust 237 against the opposing force of the governorweights. The force of the governor weights overcomes the pressure tomove the valve to the left connecting signal feed line 194 to governorline 236 and closing exhaust 237. The one way check valve 238 permitsfast flow of the governor signal pressure to the shift valves and thereturn restriction 239 only perrrrits slow return flow so the governorpressure line has fluid flow to supply without pressure drop, theexpanding governor pressure chambers when shift valves upshift andreduce return flow to prevent sharp reduction of governor pressure dueto drive line shock.

MODULATOR PRESSURE REGULATOR The modulator pressure regulator 241, FIG.5, provides a pressure inversely proportional to torque demand and has avalve element 242 having equal lands a and b mounted in a bore 243. Thespring 244 located in a spring chamber 245 vented by exhaust 246 biasesthe valve element to the open position connecting signal feed line 194between the lands to the modulated signal line 248 which is connected bya restrictive passage 249 to the chamber 250 at the end of the bore 243to act on the end of land b to bias the valve element to connectmodulator line 248 between lands a and b to exhaust 251, to regulate themodulated signal pressure inversely proportional to torque demand on theengine or the force delivered by vacuum actuator 253.

The modulator pressure regulator valve 241 is controlled by a vacuumactuator 253 consisting of a container 254 fixed to the valve body andhaving a flexible diaphragm 255 therein dividing the container into avacuum chamber 256 connected by the pipe 257 to the engine manifoldvacuum and having an atmospheric chamber 258 connected to atmosphere bythe apertures 259. The diaphragm 255 is biased by a spring 260 in thevacuum chamber and is secured to an actuator stem 261 which isreciprocally mounted in and passes through a bore or aperture in thecontainer 254 and into a bore 262 in the end wall of the valve body.Chamber 263 inbore 262 is vented by exhaust 264. The stem engages a pin265 reciprocably mounted in a bore 266 in the valve body to engage thevalve element. The force of the actuator spring 260 is inverselyproportional to the vacuum and thus increases with increasing throttleopening or torque demand and acts through the stern 261 and pin 265 onthe valve element 242 and with the regulated pressure in opposition tothe valve spring 244 to provide a regulated pressure proportional tovacuum and inversely proportional to actuator force, torque demand orthrottle opening.

FRONT GOVERNOR A front governor 267, FIG. 2, provides a pressure signalproportional to the speed of the torque converter output shaft 22 andhas a can or annular trough 268 rotatably mounted on the hub 57 and thusrotatable with shaft 22. Fluid from the lubrication system fills the canand this rotating body of fluid impinges on the opened end of the pitottube 269 to provide a pressure in the front governor line 270proportional to converter output speed for the lockup shift valve 271,FIG. 6.

10 LOCKUP VALVE The lockup shift valve 271, FIG. 6, has a valve element272 having lands a, b, c reciprocably mounted in a stepped bore 273. Thefront governor pressure line 270 is connected to closed chamber 274 toact on the end of land a to bias the valve against the bias of spring276 located in a chamber vented by exhaust 277 and having a stop andspring seat member 278. Inverted modulator pressure in line 248 actsbetween the lands 6 and c and on the unbalanced area of the larger landc with governor pressure to overcome the spring bias and upshift theshift valve. With the lockup valve in a downshift position shown, lockupapply line 281 is connected to exhaust 282 to disengage the lockupclutch 23. The valve is upshifted by governor and inverted modulatorpressure forces acting in an upshifted direction and overcoming the biasof the spring in a downshift direction. From the functional viewpoint,the lockup valve provides the shifts at higher output speeds with highthrottle setting and shifts at lower output speeds at lower throttlesettings. When the lockup cut-off valves 511 provide, as explainedbelow, a lockup feed pressure in lockup feed line 283, this pressure isconnected between the lands a and b of the upshifted lockup valve tolockup clutch apply line 281 to engage the lockup clutch. The land b isslightly larger than land a so the main line pressure connected to thelockup clutch provides a hysteresis force, so downshifts are at higherspeeds at each torque demand value. The exhaust 282 then being closed.The exhausts 282 and 284 permit leakage fluid to escape to prevent mainline leakage affecting governor or modulator pressure.

LOW ONE INHIBITOR VALVE The low one inhibitor valve 286, FIG. 4,prevents the downshift to low speed drive at speeds above apredetermined speed for smooth shifting. The inhibitor valve has a valveelement 287 having equal diameter lands a and b slidably mounted in abore 288 and biased by rear governor pressure from line 236 connected tochamber 289 at the end of the bore to act on the land a and move thevalve element against the bias of spring 291 to block the low drive boldline 197 and connect the low one shift signal line 292 to exhaust 293 toprevent engagement of low drive. Below this predetermined speed the lowone inhibitor valve is in the connecting position shown, connecting holdregulated pressure which is in the low drive line 197 when the selectorvalve is in low position, to the low one shift signal line 292 whichactuates the low one relay shift valve 298. Whenever the low brake isapplied the pres sure in the low apply line 294 is connected to theclosed spring chamber 295 to hold the inhibitor valve in the positionshown connecting low drive line 197 to low one shift signal line 292regardless of governor pressure and speed.

LOW ONE SHIFT VALVE The low one shift valve 298, FIG. 4, has a valveelement 299 having equal diameter lands a, b and c mounted in a bore 301and biased to the first drive speed position by the spring 302 mountedin a spring chamber 303 vented by exhaust 304. With the valve element inthe first speed drive position shown, the low apply line 294 isconnected to branch 305 of exhaust 1 line 306 and main line pressure issupplied from the one-two shift relay valve 378 via low one shift line307 and its branch 308 between the lands b and c to the first speedapply line 309 which is connected to the first brake cylinder 93 toestablish first speed drive. When fluid is supplied by the low oneinhibitor valve 286 to the low one shift signal line 292 to the chamber311 at the end of valve element 299 acting on land a, the valve is movedagainst the spring bias to the low drive position connecting the branch312 of the low one shift line 307 to the low apply line 294 to cylinder107 to establish low speed drive and the first apply line is connectedto branch 314 of exhaust line 306.

ONE-TWO SHIFT SIGNAL VALVE Automatic shifting between first to fourthspeed forward drives is-provided by speed and torque demand signalcontrolled shift signal valves, one for each speed change, each havingan associated relay valve. The shift and relay valves for each speedchange are similar but are individually described with the connectionsand then the operation is discussed.

The one-two shift signal valve 316, FIG. 4, has a valve element 317having land a and larger land b in a stepped bore 318 and a controlelement 319 having lands a, b and c of increasing diameter from a to cmounted in a stepped bore 321. The land b of valve element 317 is largerthan land a so that when the valve is moved from the downshift positionshown in FIG. 4 to the upshift position connecting main line 117 to theone-two signal line 322 for a shift to second speed, there is an addedhysteresis force in an upshift direction on the valve. In the downshiftposition shown, the oneto signal line 322 is connected to exhaust 323and this hysteresis force is dropped. In both downshift and upshiftpositions, gear governor pressure from line 236 enters chamber 324 atthe end of bore 318 and acts on land a of valve element 317 in anupshift direction. Also modulator pressure line 248 is connected to thestepped bore between the large land c and the smaller land b of controlelement 319 to also provide an upshift direction force. Both thegovernor and modulator upshift direction forces are opposed by thedownshift direction force of spring 325 which is mounted on a suitablespring seat and stop assembly 326 in a spring chamber 327 vented byexhaust 328. When governor pressure and modulator forces overcome thespring force, both valve elements upshift and the modulator pressurefrom line 248 is also connected between land a and b of the controlvalve element 319. Since land b is larger than the land a there is anadditional area and upshift force after upshifting to control thedownshift. The two-one downshift line 329 may supply either holdpressure from the drive one line 198 or detent pressure from detent line174 and is connected via branch 330 to hold the shift valve element 317in the downshift position when downshifted or via branch 331 when thevalve element is upshifted to downshift the shift valve element at apredetermined speed. The regulated hold pressure supplied isinsufficient to downshift above a predetermined speed for a propershift.

The two one downshift line 329 is supplied in a detent position of thethrottle pedal by detent valve 162 and detent line 174. If the slightlyhigher hold pressure from hold regulator valve 209 is connected by theselector valve 191 in the drive one position to drive one line 198, theone two shuttle valve 332 blocks detent line 174 and connects holdpressure from drive one line 198 to downshift line 329. The shuttlevalve 332 has a ball 333 located in a chamber 334 having a bottomsurface having depressed seat port 335 at the entry of detent line 174to the chamber and closely adjacent depressed seat port 336 at the entryof drive one line 198. The downshift line 329 is connected to chamber334 by a port that is wide and positioned so it cannot be blocked byball 333. When pressure is supplied to one of seat ports 335 or 336, theball will seat in and close the other. The chamber has a rounded uppersurface particularly at the ends to guide the ball into the seat portsand the height of the chamber between the seat ports should be onlyslightly greater than the ball diameter.

TWO-THREE SHIFT SIGNAL VALVE The two-three shift signal valve 341 has avalve element 342 having lands a, b and c of increasing diameter from ato c in a stepped bore 343 and a control element 334 having lands a, band c of increasing diameter from a to c in a stepped bore 345. In boththe up and down shift positions of the shift valve, the governorpressure line 236 is connected to the chamber 346 to provide an upshiftdirection force and the modulator pressure line 248 is connected betweenthe lands b and c of control element 344 to act on the excess area ofland c to pro vide an upshift force against the downshift directionforce of spring 347 mounted on a seat assembly 348 in the spring chamber349 which is vented by exhaust 351. Exhaust 352 vents a space betweenlands b and c of valve element 342. Exhaust 353 exhausts the twothreesignal line 354 with the valve element 342 in the downshift positionshown so there is no two-th ree signal pressure for a shift to third. Onan upshift exhaust 353 is closed and main line 117 is connected to thetwo-three signal line 354. With the shift valve 342 and control valve344 in the downshift position shown or upshift position, governorpressure from line 236 in chamber 346 acting on land a and modulatorpressure from line 248 acting on land c of control valve 342 provides anupshift direction force against the downshift force of spring 347 toprovide upshifts. When the governor pressure and modulator pressureovercome the spring force, the shift valve 342 and control valve 344move to the upshift position. Then main line pressure acting on land bwhich is larger than land a provides an upshift hysteresis force andmodulator pressure acting on land b provides an added upshift force toprovide downshifts at speeds lower than upshift speeds. The three twodownshift line 355 in the downshift position of the shift valve and thebranch 356 in upshift position of the shift valve is connected to thevalve bore between the shift valve element 342 and the control valveelement 344, for downshifting the shift valve element when supplied withhold or detent pressure. The detent pressure line 174 and the holdpressure via drive two line 199 are connected to the two three shiftshuttle valve 357 which has the same structure as the one two shuttlevalve 332 and thus has the same reference numbers primed. When thethrottle pedal is in detent position providing detent pressure in line174 shuttle valve 357 connects this pressure to the three-two 13downshift line 355 but if the selector valve 191 is in drive two orlower positions providing hold pressure in line 199 this pressure issupplied to downshift line 355 and detent pressure blocked.

THE THREE-FOUR SHIFT SIGNAL VALVE The three-four shift signal valve 358,FIG. 4 has a shift valve element 359 having lands a, b and c located ina stepped bore 361 and a control valve element 362 having lands a, b andc in a stepped bore 363. The lands of both valve elements havesequentially increasing diameters from a to c. Both valve elements arebiased to the downshift position by a spring 364 located in a springchamber 365 vented by exhaust 366. The spring is seated on an adjustableseat 367 and having a stop pin 368 limiting valve movement. in thedownshift position, shift valve element 359 blocks main line 117 andconnects the three-four shift signal line 371 to exhaust 372. In thisposition, governor pressure acting in chamber 373 on the land a of valveelement 359 and modulator pressure line 248 acting on the land c ofcontrol valve element 362 provide a force in the upshift directionagainst the downshifi direction force of the spring 364. When governorand modulator pressure overcome the spring force, the valve elementsupshift. ln upshift position land a of valve element 359 blocks exhaust372, main line 117 is connected to the three four shift signal line 371and the main line pressure between lands a and b acts on the larger areaof land b to provide a primary additional upshift hysteresis force. Inaddition, modulator pressure also acts on land b of control valveelement 362 to provide an additional upshift force causing downshifts atlower speeds. The exhaust 374 vents the valve bore between the downshiftline 375 and main line 117. Hold or detent pressure in the three-fourdownshift line 375 and its branch 376 is connected between the valveelements when in the downshift and upshift position respectively toposition valve element 359 in a downshift position at proper speeds.When detent pressure is supplied to line 174 the three-four shuttlevalve 377 connects it to fourthree downshift line 375 unless theselector valve is in drive low, one, two or three positions and suppliesthe higher hold pressure to drive three line 201 which is then connectedto downshift line 375 and detent pressure is blocked. This shuttle valve377 has the same structure and operation as shuttle valve 332 so theparts have the same reference numerals double primed.

ONE-TWO RELAY VALVE The one-two relay valve 378, FIG. 3, has a valveelement 379 having equal diameter lands a, b and c located in a bore 381and is biased to the first speed position shown by a spring 382 seatedon the spring seat 383 located in a closed chamber 384. The chamber 384is connected by a port 386 and a passage 387 through the valve elementto a port 388 located in a groove 389 in the land a to exhaust thechamber in the upshift position. Main line pressure supplied from theselector valve 191 to the drive four line 203 is always connectedthrough restriction 391 in the priority valve 392 to the priority mainline 393. The priority valve has arranged in parallel with restriction391 a relief valve having a valve element 394, closing port 395 underthe bias of spring 396 in vented chamber 397 when the pressure in mainline and drive four line 203 is insufficient for properly operating thetransmission and open when the pressure is sufficient. The valve willclose momentarily during shifts involving engagement of second, thirdand fourth in forward drives to maintain sufficient main line feedpressure to the modulator valve 253 and governor valve 223. Therestriction 391 provides an exhaust connection in neutral position ofthe selector valve.

Relay valve 378 in the first speed position shown, connects the one twoshift line 398 to exhaust line 306, blocks priority drive four line 393,connects the main line 1 17 via restriction 399 between the lands b andc to the low first shift line 307, blocks restricted branch 402 ofexhaust line 306 at the land c and connects reverse drive line from themanual selector valve adjacent land c to the spring chamber 384 which isclosed since passage 387 is blocked. When the one-two shift signal valve321 provides pressure in the one-two signal line 322 to supply fluid tothe closed chamber 401, valve element 379 is moved against the bias ofthe spring except in reverse to the second speed position. Then springchamber 384 is connected via passage 387 to exhaust line 306, prioritydrive four line is connected to the one-two shift line 398, main line117 is blocked by land b, the low first shift line 307 is connected viarestricted branch 402 to exhaust line 306 and reverse line 195 isblocked by land 0.

TWO-THREE RELAY VALVE The two-three relay valve 406 has a valve element407 having equal diameter lands a, b and c located in a bore 408 andbiased by a spring 409 to the downshift or second speed position shownin FIG. 3. The spring is seated on a seat and pin assembly 41 1 in achamber 4 l2 vented by exhaust 414. When the relay valve is biased bythe spring to the second speed position, the twothree shift feed line415 is connected between lands a and b via branch 416 to exhaust line306, one-two shift line 398 has unrestricted branch 417 blocked by landb and the restricted branch 418 and exhaust flow only check valve branch418' connected between lands b and c to the second brake line 419 andrestrictive branch 421 of the exhaust line 306 is blocked by land 0. Thecheck valve branch blocks flow from line 398 to the valve bore since theball can seat in the outlet port to the valve bore 408 and permits freeunrestricted flow from the valve bore 408 to line 398 since the outletport for flow from the valve bore 408 is so close to a side wall thatthe ball cannot seat in this port. Both restricted branch 418 andunrestricted or less restricted check valve or check valve branch 418'are connected to the same port in bore 408. The check valve branch 418'provides only an exhaust passage while restricted passage 418 is a feedonly passage. When the two-three shift signal valve 341 supplies thetwo-three shift signal line 354 pressure to chamber 422, the two-threerelay valve element moves against the spring to the stop pin and exhaustbranch 416 is blocked by land a. The onetwo shift signal line 398 viabranch 417 is connected to the two-three shift line 415, the restrictedbranch 418 and check valve branch 418' are blocked by land b and thesecond brake line 419 is connected via restricted branch 421 to exhaustline 306.

l THREE-FOUR RELAY VALVE The three-four relay valve 424 has a valveelement 425 having equal diameter lands a, b and c located in a bore 426and is biased by a spring 427 to the third posi tion shown in FIG. 4.The spring is located in the chamber 428 vented by exhaust 429 andseated on a seat and valve stop assembly 431. When the valve element 425is biased to the third position shown by the spring. reverse drive line195 is connected between the lands a and b to the fourth clutch lines432, the twothree shift signal line 415 has restricted branch 434blocked by the land b and restricted branch 435 and exhaust flow onlycheck valve branch 435 connected between lands 4': and c to the thirdbrake line 436 and the exhaust line 306 connected by restriction 437 isblocked by land c. Check valve branch 435' is constructed and functionslike check valve branch 418'. When the three-four shift signal valve 358provides a signal pressure in the three-four shift signal line 371 tothe chamber 438, this pressure acts on land a moving the valve to thefourth speed position. Then reverse drive line 195 is blocked by land a,to-three shift line 415 is connected by restrictive branch 434 to thefourth clutch line 432 and branch 435 and check valve branch 435' areblocked by land b and the third brake line 436 is connected viarestriction 437 to exhaust line 306.

TRIMMER REGULATOR VALVE The trimmer regulator valve 441, FIG. 3, has avalve element 442 having equal diameter lands a, b, c and larger land oflocated in a stepped bore 443 and is biased to the feed position shownby a spring 444 seated on an abutment and stop pin assembly 446 locatedin a spring chamber 447 vented by exhaust 448. With the valve element442 in the feed position shown, main line I17 branch 451 is connectedbetween the lands b and c to the trimmer regulated pressure line 452which is connected by branch 453 which may be restricted to the closedchamber 454 to act on the end of land a and oppose the spring bias andregulate the pressure. When the trimmer regulated pressure exceeds theregulated value, it will move the valve element 442 to the leficonnecting trimmer regulator pressure line 452 between lands a and b toexhaust 456. The modulator pressure line 248 is connected between thelands c and d to act on the unbalanced area of land d TRIMMER VALVES Thefirst and reverse drive trimmer valve 461 has a trimmer regulatorelement 462 having a small land a and large land b located respectivelyin small bore 463 and large bore 464. The first brake apply line 309 isconnected by branch 466 to the end of the bore 463 and acts on land a tobias the valve to the right to the open position connecting first brakeapply line 309 to exhaust 467 to reduce the pressure. First brake applypressure from line 309 is continuously connected through restriction 468to the space 469 between the regulating valve element 462 and anactuator plug 471 which is shown seated on a stop member 472 fullycompressing the spring 473 located in a closed chamber 474 havingtrimmer regulator pressure connected thereto at a port 475 below thestop and thus never blocked by plug 471. When line 309 is vented, spring473 is extended with plug 471 engaging regulator valve element 462. Onthe initial supply of fluid to the first brake by first brake apply line309, pressure acts on regulator valve element 462 and is regulated at alow pressure value determined by the trimmer regulator pressure whichincreases with increasing torque demand and the minimum spring force atfull height in the valve assembly. At the same time fluid slowly flowsthrough restriction 468 to fill and enlarge the space 469 to graduallyseparate the regulator valve element and plug so that the spring 474 ismore and more compressed to gradually increase the regulated pressure ata rate determined by the restriction and spring rate until the maximumregulated pressure is provided with the valve elements in the positionshown for gradual engagement of the friction devices. Then the pressurequickly increases to main line pressure. The valve will remain in thisposition until the first brake apply line 309 is exhausted and the valvewill return to the initial position. The use of trimmer regulatorpressure makes it possible to individually set the low pressure and rateof pressure rise to meet the requirements of each friction device withthe same valve structure and springs fitting therein.

The second speed trimmer valve 476 similarly has a regulator valveelement 477 having small land a and large land 6 respectively located insmall bore 478 and large bore 479. Second brake pressure in line 419 isconnected by branch 481 to the end of bore 478 and acts on the land a tomove the regulator valve 477 and the plug 482 against bias of spring 483and trimmer regulator pressure from line 452 and port 489 in chamber 487to connect line 481 to exhaust 488 to reduce the pressure. The stopelement 484 limits movement of the plug 482 and compression of thespring 483. When pressure is supplied via line 481 to the bore, it alsoflows through restriction 485 to the space 486 between the regulatorvalve and plug to enlarge this space to increase the spring force togradually increase the pressure like first and reverse drive trimmervalve 461.

The third speed trimmer valve 496 has the same construction andfunction. Primed numbers from the second speed have been used toindicate like parts. This valve controls the third brake apply line 436pressure which is connected by branch 497 and acts on the land a ofregulator valve element 477' which moves to open exhaust 488. Thetrimmer regulator pressure line 452 is connected to port 488'. Thefourth clutch trimmer valve 501 is similar to the above trimmer valvesand functions in the same way and thus the same reference numerals withdouble primes have been used. The fourth clutch trimmer valve 501regulates the fourth clutch pressure in line 432 and exhausts the excessto exhaust 488" and is controlled by trimmer regulator pressure fromline 452 connected to port 489".

CUT-OFF VALVES The lockup cut-off valves 511 provide a feed to thelockup clutch feed line 283 whenever fluid is supplied to any frictiondevice, i.e., clutch or brake, apply line. A first cut-off valve 512 hasa valve element 514 located in a bore 515 having closed ends and arestricted inlet port 516 at one end, an intermediate free flow inletport 517, a central outlet port 518, an intermediate unrestricted inletport 19 on the other side of the central outlet port and anotherrestricted inlet port 521 at the opposite closed end of the bore. Therestricted inlet port 516 is connected to an expansible chamber 522formed by the one closed end of the bore and the valve element whilenear the one end and the restricted inlet port 521 is connected to anexpansible chamber 523 formed by the other closed end of the bore andthe valve element while near the other end. A second cut-off valve 525and third cut-off valve 531 have a similar construction and the partsare indicated by primed numbers, except that in the first and secondlockup cut-off valves $12 and 525, a single central port 518 is used,while in the third lockup valve 531 the bore is longer and has spaceddual central ports 532 and 533. The first cut-off valve 512 has thefourth clutch apply line 432 connected to inlets 516 and 517 and thethird brake apply line 436 connected to inlets 519 and 521. In forwarddrives, pressure is supplied only to one of the first, second, third,and fourth apply lines respectively, 309, 419, 436 and 432, and theothers exhausted. Thus, when one apply line has been under pressure forthe time delay period or was the last line to be pressurized, i.e. thirdapply line 436, the valve element 514 is at the other end, i.e. atchamber 522, and blocks the other inlet port, i.e. inlet port 517,connected to fourth apply line 432 and connects the one pressurizedapply line to the central outlet port, i.e. connects third apply line436 by both inlet ports 519 and 521 to central outlet port 518. Thecut-off valves are located horizontally so they will normally stay inthe position in which they are set by fluid pressure. Then on a shift toanother speed drive, i.e. to fourth, the one apply line, i.e. thirdapply line 436, is exhausted, decreasing the pressure while pressure issupplied to the other apply line, i.e. to fourth apply line 432,increasing the pressure. When the increasing fourth apply pressure inchamber 522 is greater then the exhausted third apply pressure inchamber 523, the lockup feed line is exhausted via outlet port 518 toexhausted third apply line 436 to disengage the lockup clutch and thefourth apply pressure feed through restricted inlet 516 slowly movesvalve element 514 toward the other end and first blocks outlet port 518after the lockup clutch is disengaged at the initiation of the shift andthen valve element 514 moves further to open inlet port 517 whereuponfull fourth apply pressure flow quickly moves valve element 514 toconnect this pressure to outlet port 518 to re-engage the lockup clutcha predetermined time delay period after disen gagement. Thus, firstcut-off valve 512 supplies either pressure after a time delay period ifthe other pressure was last previously supplied or without time delay ifthe same pressure was last previously supplied. The outlet port 518 isconnected by transfer line 536 to the ports 516' and 517' of the secondcut-off valve 525. The second brake apply line 419 is connected to theports 519 and 521' of the second clutch cut-off valve 425 whichfunctions like cut-off valve 512 and thus supplies either third orfourth apply pressure connected to one group of inlet ports or secondapply pressure supplied to the central port 518' whenever fluid issupplied by transfer line 536 or second apply line 419. The supplythrough cut-off valve 525 will be delayed or immediate as in cut-ofi'valve 512.

Central port 518' of second cut-off valve 525 is connected by transferline 537 to the ports 519" and 521" of the third cut-off valve 531. Thefirst brake apply line 309 is connected to the ports 516" and 517" ofthird cut-ofi' valve 531. Thus, whenever fluid is supplied to either thetransfer line 537 or the first brake apply line 309, fluid is connectedto spaced outlet ports 532 or 533 to supply the lockup clutch feed line283. Valve 531 has outlet ports 532 and 533 spaced about the length ofthe valve element 514" so that fluid pressure being exhausted remainsconnected to the lockup feed line 283 substantially until the fluidpressure being increased is connected when this valve acts to provide atime delay. Thus, this valve provides a longer lockup clutch exhaustperiod. Whenever fluid is supplied to any of the first, second, third orfourth apply lines on a shift from a next higher or lower speed drive,there is a calibrated time delay before fluid is supplied to the lockupclutch feed line. In normal shifting between N and the forward ranges,lockup disconnect and subsequent apply is controlled during the shiftsone-two, three, three-four, four-three, threetwo, two-one and will becontrolled respectively by orifices 521", 516', 516, 521, 521' and 516",so if different time delays are required each orifice may be sized toprovide a proper time delay for each shift. After reverse drive only,cutoff valve 512 will be differently positioned so a twothree shiftwill, only on the first shift, have a longer delay. This is not aproblem but could be avoided by connecting reverse line by a shuttlevalve not shown to line 436 downstream of valve 512.

RETARDER YALVE The retarder valve 541 controls the operation of thehydrodynamic brake 30. There is a valve element 542 having lands a, band c of equal diameter located in a bore 543 and is biased to thebrake-off position shown by pressure located in a chamber 558. inbrake-off position, the retarder in-line 548 is connected between thelands a and b to the restricted exhaust line 549 connected to exhaust547. The cooler out-line 154 is blocked by land b, the retarder out-line551 is connected between lands b and c to exhaust 552 and via exhaustpassage 553 to exhaust S54. Converter out-line 156 is connected bybranch 556 and blocked by land 0. The main line 117 is connected by arestriction 557 to the chamber 558 at the end of bore 559 having a plug56] therein which acts on the valve element 542 when chamber 558 ispressurized. The manually controlled solenoid valve 560 is normallyspring closed to pressurize chamber 558 and position the brake valve 542in the position shown, the brake-ofi' position. When the solenoid valve560 is energized to vent chamber 558,

the spring 544 moves the valve 542 to the left, to the brake-onposition, connecting cooler out-line 154 to retarder in-line 548, andretarder out-line 551 to the branch 556 of converter out or coolerin-line 156. Retarder out-line S1 always connects to a spring loadedpressure relief valve 564 or torque limiter valve which regulates theretarder out-pressure at a low value to provide a controlled amount ofhydrodynamic braking.

OPERATION When engine driving this transmission is running, thetransmission input driven pump 112 FIG. 6, supplies fluid under pressureto the main line 117 which is regulated at a normal line pressure value,i.e. 180 psi when the transmission is in forward drive and forward driveknockdown pressure is supplied via line 136 to the regulator valve andat a higher reverse drive pressure i.e. 300 psi in reverse drive whenthis knockdown pres sure is not supplied. The regulator valve exhaustline 136 is connected through restriction 137 to the lubrication line138 which lubricates the transmission gearing and supplies fluid to thepitot tube governor 267. The exhaust line 136 is maintained above alower pressure value i.e. 80 psi to properly feed the lubrication systemand excess fluid is then bypassed by lubrication regulator valve 139 tothe converter feed line 146 which is also supplied with fluid by asecond input pump 147. The converter feed pressure in line 146 isregulated at a low pressure, i.e. 62 psi by the converter by-pass valve150 which bypasses overage to the cooler outlet line 154. The converteroutlet flow in line 156 passes through the cooler 160 to the cooleroutlet line 154. The converter regulator valve 157 regulates the cooleroutlet line at a low pressure, i.e. 25 psi to control converter outletpressure. When the brake valve 541, FIG. 2, is in the brake-on position,the cooler outlet line is connected to supply the hydrodynamic brake 267at the pressure regulated by the converter regulator valve. ln thebrake-off position, shown, the cooler outlet line 154 is blocked andoverage fluid flows via exhaust 161 to sump l 11.

In neutral position, the manual selector valve 191 supplies fluid to theforward knockdown line 136 and the signal feed line 194 and the otherlines, reverse 195, low 197, first 198, second 199 and third 201 drivelines are connected to exhausts 196 or 202 directly, while the drivefour line 203 is connected to the hold feed line 204 and both areexhausted via the hold regulator valve 209 and the drive three feed line201 to exhaust 202. As explained above, the trimmer regulator valve 441will supply trimmer regulator pressure to line 452, the modulatorpressure regulator valve 241 will provide modulator pressure in line 248inversely proportional to torque demand and the transmission outputgovernor valve 223 will provide a governor signal in line 236 that is afunction of output speed. The hold pressure regulator valve is notsupplied and thus there is no hold pressure in line 217 and there is nodetent pressure in line 174. Also the pitot tube governor 267 provides aconverter output speed signal in line 270 that is a function ofconverter output speed.

Normally when the selector valve is in neutral position the output orvehicle driven thereby will be stationary or nearly so and the engine isrunning to pressurize the system as pointed out above, the outputgovernor pressure and modulator pressure will be insufficient toovercome the downshift bias of the springs so the one-two, two-three andthree-four shift signal valves 316, 341 and 358 will be in the downshifiposition connecting the two, two-three and three-four shift signal lines322, 354 and 371 to exhausts 323, 353 and 372 respectively. The mainline 117 is directly connected to each shift signal valve and blocked byland b thereof. Since there are no shift signal pressures the one-two,two-three and three-four relay valves 378, 406 and 424 are spring biasedto the downshift or lower speed position. Since there is no low drivepressure in line 197, the low one shift valve 298 is spring biased tothe higher or first speed position. The main line is then directlyconnected by restriction 399 and the downshifted one-two relay valve 378to the low one shift line 307 which is connected by the upshifted lowone shift valve 298 to the first brake apply line 309 to 20 engage thefirst brake 89. Thus, when the engine is modulator pressure controlsystem will function as during automatic shifting described below toposition the shift signal valves and relay valves in accordance withspeed and torque demand. When the one-two relay valve 378 upshifts,first brake apply line 309 is connected by the low one shift valve 298to the low one shift line 307 which is connected by the one-two relayvalve 378 to exhaust 402 to disengage the first brake 89. Since drivefour line 203 is exhausted at the selector valve in neutral position,the second and third brakes and fourth clutch cannot be applied. Thus onmovement of the selector valve to a drive position, the forward clutchwill be engaged and the priority valve 392 will supply fluid to thenengage the drive speed selected by the automatic controls. The drive andcoasting shift engagement sequence is the same, the drive always beingcompleted by the second, third or fourth speed engagement device.

On shifting the manual selector valve 191 to the $0 drive four positionDR4 at output speeds and torque demand values insufficient to upshiftthe one-two shift signal valve 316, the main line 117 is directlyconnected to the drive four line 203 to directly supply fluid to engagethe forward clutch 51 to engage the first speed drive since the firstbrake B9 was engaged in neutral and remains engaged. Thus when theoutput or vehicle is standing or moving very slow the forward clutchinitiates the drive on a neutral to drive four position or any forwarddrive position. The drive four line also supplies fluid to the priorityvalve 392 which feeds the drive four priority line 393 which in thefirst speed position of one-two relay valve 378 is blocked by the landb.

The other drive establishing devices are exhausted to disestablish theother drives. The low brake apply line 294 is connected by upshifted lowone shift valve 298 to exhaust 305, 306. The second speed brake applyline 419 is connected by the downshifted two-three relay valve 406, viacheck valve branch 418' to one-two shift feed line 398 which isconnected by downshifted onetwo relay valve 378 to the exhaust line 306for disestablishing the second speed brake 82. The third speed brakeapply line 436 is connected by the downshifted three-four relay valve424 to the restricted branch 435 and check valve branch 435' to thetwothree shift feed line 415 which is connected by the downshiftedtwo-three relay valve to the exhaust branch 416 and line 306 todisengage third brake 76. The fourth speed clutch apply line 432 isconnected via the downshifted three-four relay valve 424 to the reverseline 195 which is connected to exhaust at the selector valve 191 todisengage the fourth clutch 63.

When the speed of the vehicle increases, so that governor pressure inline 236 upshifts the one-two shifi signal valve 316 against the springbias reduced by modulator pressure from line 248, the exhaust 323 isclosed and the main line 117 supplies pressure to the one-two shiftsignal line 322 which acts in chamber 401 to upshifl the one-two relayvalve 378 from the downshifted position against the spring bias to theupshifted position. Upshifted one-two relay valve 378 connects the lowone shift line 307 which had engaged first speed via the low one shiftvalve 298 to the exhaust line 306 to disengage first speed and connectthe priority main line 393 between lands a and b to the one-two shiftfeed line 398 which is connected by the restricted branch 418, the checkvalve branch 418' being closed, between the lands b and c of thedownshifted two-three relay valve 406 to the second brake apply line 419for engagement of the second speed.

At a higher speed, governor pressure similarly upshifts the two-threeshift signal valve 341 which will disconnect the second third shiftsignal line 354 from exhaust 353 and connect it to main line. The secondthird shift signal line 354 is connected to chamber 422 of two-threerelay valve 411 to upshift this valve to the upshift position connectingthe second brake apply line 419 by restricted exhaust 421 to the lowpressure exhaust line 306 and connects the unrestricted branch 417 ofthe one-two shift line 398 to the second third shift feed line 415 whichis connected via restricted branch 435, the check valve branch 435'being closed, and between the lands b and c of downshifted three fourrelay valve 424 to the third brake apply line 436 to engage third speeddrive.

At a still higher speed the governor pressure will upshift thethree-four shift signal valve 358 to disconnect the three-four shiftsignal line 371 from exhaust 372 and connect it to main line 117 tosupply pressure to the chamber 438 to upshift the three-four relay valve424. This upshifted relay valve will then connect third brake apply line436 to restricted exhaust 437 and the low pressure exhaust line 306 andconnect the twothree shift feed line 415 via restriction 434 to thefourth clutch apply line 432 to engage fourth speed drive.

Since the drive four line via the priority valve 392 and priority drivefour line 393 sequentially feeds the one-two, two-three and three-fourrelay valves only one of the first, second, third and fourth speeds canbe engaged and failure of any shift relay valve to upshift will preventengagement of all higher speed drives. Since the shift signal valvesupshift sequentially with increasing speeds, the drives will be changedin this sequence.

A reduction of governor pressure and/or modulator pressure will effect adownshift of the shift signal valves sequentially, the three four shiftsignal valve, the twothree shift signal valve and then the one-two shiftsignal valve to provide the reverse of the above described upshiftingoperation and thus provide downshifting in this sequence.

During quick deceleration where substantially simultaneous downshiftingof the two higher shift signal and relay valves may occur, the drivespeed of the lowest relay valve that is downshifted will be establishedand thus a four to second or first speed shift can occur.

The lockup clutch 23 is engaged in each forward ratio by the lockupvalve 271 when upshifted by input governor pressure in line 269 suppliedby the pitot tube governor 267 acting against the modulator pressuremodified spring bias to engage the lockup clutch in each ratio when thetorque converter output speed indicates the torque converter isoperating in the coupling stage and a shift change is not in progress.When a range shift change is in progress the lockup feed line is brieflyexhausted to one of the exhausted apply lines and after a time delaysupplied with main line pressure from the one pressurized apply line bythe lockup cut-off valves as explained above. Only one of the firstspeed apply line 309, the second speed apply line 419, the third speedapply line 436 or the fourth speed apply line 432 is pressurized inforward drives and the others exhausted. The two highest drive applylines are connected to a first cut-off valve which is connected with thenext lower speed apply line to the next sequentially connected cut-offvalve. Thus normally on each shift between forward drives, there ispredictable valve movement first exhausting and then, after apredetermined delay, feed to the lockup feed line 283. When fluid issupplied by lockup feed line 283, the upshifted lockup valve 271connects this line to the lockup apply line 281 to engage the lockupclutch. In the downshift position, lockup apply line 281 is connected toexhaust 282.

When the throttle pedal is in the through detent position which may beeither just prior to, at, or just beyond full throttle position, throughdetent valve 162 supplies to the detent line 174 fluid at a regulatedpressure to each of the four-three shuttle valve 327, three-two shuttlevalve 357 and two-one shuttle valve 332. if the hold feed pressuresupplied by line 204 in the manual valve via the drive three line 201,drive two line 199 and drive one line 198 respectively is present in anyof these valves, the detent pressure being lower will be blocked butotherwise detent pressure will be transmitted to the shift valves.However, if the hold feed pressure is not present in any of thesevalves, the detent pressure will, as explained above, move the ball 333from the detent line seat 335 to the hold feed pressure seat 336 and thedetent pressure will be connected to the downshift line connected tothat shuttle valve. As pointed out above, the four-three downshift line375, the three-two downshift line 355 and the two-one downshift line 329are respectively connected to the three-four shift signal valve 358, thetwo-three shift signal valve 341 and the one-two shift signal valve 316and will provide up and down shifts of each of these shift valves at ahigher speed than the normal shift speeds and remove the normaldownshitt bias by the spring modified by modulator pressure.

Movement the manual selector valve 191 to the drive three position DR3,in addition to supplying previously supplied signal feed line 194,forward knockdown line 136 and drive four line 203 also feeds the holdfeed line 204 and blocks the exhaust of the drive three feed line 201.Thus the hold pressure is regulated by the hold regulator valve 291 whensupplied with main line pressure by the hold feed line 204 and supplieshold pressure via line 217 to the drive three feed line 201 which isconnected by four-three shuttle valve 377 regardless of the presence orabsence of detent pressure to the four-three downshift line 375 whichwill downshift the three-four shift signal valve at a higher speed thandetent pressure. The shift valves control the slave valves for shiftingthe transmission as in automatic drive but up and downshifts from thirdto fourth speed occur at a speed higher than detent shift speed. Thusnormal power driving would be limited to first to third speeds but coastupshifts to fourth are permitted.

Movement of the manual selector valve 191 to the drive two position DR2will additionally interconnect the drive three line 201 to supply holdpressure to the drive two line 199 which will be connected by thethree-two shuttle valve 357 to the three-two downshift line 355 whichsimilarly acts on the two-three shift signal valve 341 to control thetwo-three relay valve 406 for shifting the transmission at a higherspeed than detent shifting, so normal power one-two shifts are providedwith coast upshifts to third and fourth.

Movement of the manual selector valve 191 to the drive one position DR!additionally connects hold pressure from drive three feed line 201 tothe drive one line 198 which is connected by the two-one shuttle valve581 to the two-one downshift signal line 329 which acts on the one-twoshift signal valve 316 to control the one-two relay valve 378 to shiftthe transmission between first and second speeds at higher speeds thanthe detent downshift to normally hold first speed but permit coastupshifts.

Further downshift of the selector valve 191 to the low position LOW willconnect the hold pressure in the drive three feed line 201 to the lowdrive line 197 which at low speeds, proper for such a downshift, will beconnected by the low one inhibitor valve 286 to the low one shift signalline 292 which will downshift the low one shift valve 298 to the lowposition connecting first apply line 309 to exhaust and connecting thelow one shift signal line 307 via branch 312 to the low brake line 294to establish low ratio. The low speed apply pressure line 294 isconnected to closed spring chamber 295 of the low one inhibitor valve286 so an increase in speed while the transmission is operating in lowspeed drive will not cause an upshift to first speed drive. If thetransmission output or vehicle speed is too high for a proper firstspeed drive to low speed shift, governor pressure in line 236 willactuate low one inhibitor valve 286 to block low drive pressure line 197and connect the low one shift signal line 292 to exhaust 293 to preventa downshift of the low one shift valve 298. This proper speed for afirst to low shift is less than lockup speed.

Movement of the selector valve 191 from the low position to the driveone position will permit a manual upshift from low to first speed drive.Such shifts above the inhibitor speed only occur during coasting andthere is no disengagement of the lockup clutch. Further movement ofselector valve 191 in an upshift direction through the drive ranges willpermit upshifts to the last drive speed included in each range at normalshift speeds and shifts to higher speeds at the higher hold shiftingspeed.

In order to make a shift to reverse the selector valve must be firstmoved to neutral, placing the control system in the above describedneutral condition, and then to reverse R. In the reverse position R, theselector valve 191, exhausts the drive four line 203 and forwardknockdown line through the hold feed line 204, the hold regulator valve209 and drive three line 201 to exhaust 202. Exhausting the forwardknockdown line 135 causes main pressure regulator valve 119 to increasemain line pressure in line 117 to a higher value, i.e. 300 psi.Exhausting the drive four line 203 as in neutral prevents establishingof the forward clutch 51, the the second brake 82 and the third brake76. It also exhausts the normal forward drive feed through the relayvalves, which through the two-three shift line 415 with the three-fourrelay valve 424 upshifted feeds the fourth clutch apply line 432 or whendownshifted the third brake apply line 436. To establish reverse drivethe three-four relay valve must be in the downshifted or third speedposition. Then the selector valve 191 in reverse position connects mainline 117 to reverse line 195, which with the three-four relay valve 424in the downshift position, is connected to the fourth clutch apply line432 to engage the fourth clutch. in addition, to establish reverse, thefirst brake 89 must be applied. If the transmission output is running atspeeds sufficient to call for establishment of second or higher speedsby the automatic control system exhausting the drive four line 203places the transmission in neutral. When the speed reduces to a very lowvalue sufficient for a downshift of the one-two signal valve 316 andone-two relay valve 378, the latter connects main line 117 through thelow first shift line 307, the low one shift valve 398, the first brakeapply line 309 to engage first brake 89 to establish reverse drive.

In reverse, the lockup cut-off valves are non-func tional since thereare no shifls and it is immaterial whether there is a lockup feedpressure in line 283 since the lockup valve 271 does not shift becausereverse speed in insufficient.

It should be noted that during range shifts between first, second, thirdand fourth speeds, each of these speeds is established by a feedrespectively through only one of the restrictions 399, 418, 435 or 434which is the proper size flow controlling passage portion for thatshift. In the lower speed relay shift valves only the low speed inlet isrestricted and in the highest speed relay shift valve both the low andhigh speed inlets are restricted. These restrictions control ordetermine the total restriction of the line or flow passage to eachratio motor during the engagement thereof on both upshifts anddownshifts, to control the flow in accordance with the requirements ofeach motor which are different from each other due to motor volume,whether the motor is rotary or stationary and the shift characteristics,to provide good shift characteristics. Also each relay valve has a lowand a high exhaust. 0n upshifts to the next higher speed, the first,second and third speed devices are exhausted respectively by lowexhausts having restrictions 402, 421 and 437 so each restriction isproperly sized to control the disengagement of the previously engagedlower speed. n downshifts to the next lower speed the exhaust fromsecond, third and fourth is respectively through (second) substantiallyfree clutch valve passage 418' and a free or restricted high exhaust 306of one-two relay valve 378, (third) check valve passage 435' and free orrestricted high exhaust 416 of the two-three relay valve 406 and(fourth) free high exhaust to reverse feed restriction 208 which isquite large or may be a free passage with check valve ball 207. Thecheck valve passages 418' and 435' provide a free exhaust or returnbypass, respectively, of restricted inlets 418 and 435 and prevent feedflow bypassing restricted inlets 418 and 435 so they control ratioestablishment. The check valves have a ball which seats on and seals theoutlet to its inlet line between the restriction and the valve suppliedduring feed flow but during return or exhaust flow the ball cannot seaton the other port leading to the inlet line, now used as an exhaust onthe other side of the restriction, providing bypass flow of therestriction. Thus on upshifts which are under power both the feed andexhaust for both establishment and disestablishment of each speed driveare individually timed by a particular restriction. On a downshift theinlet restrictions 418 and 435 are suitable but the paralleled freereturn check valve respectively 418' and 435' provide a free return soon a downshift each speed device is controlled by its own preselecteddownshift exhaust.

Thus, for engagement of each speed device the feed on both upshift anddownshift is through a preselected restricted passage having acalibrated restriction for each speed and excluding or bypassing thecalibrated feed and exhaust restrictions for the other speeds. Theexhaust passages for disengagement during both upshift engagement of ahigher speed and downshift engagement of a lower speed, each have apreselected calibrated restriction for each speed, one for upshift andone for downshift, and each exhaust passage excludes all feedrestrictions and any other exhaust restrictions. Exhaust restrictionrequirements for each motor differ for similar reasons as stated abovefor feed requirements but the downshift exhaust requires a higher flowrate, less restriction than either upshifi exhaust or feed for goodshift timing. Thus in building a transmission, the restriction of eachdownshift exhaust passage is the least so it is desirable to build thesepassages to provide the proper large flow rate downshift exhaust passagefor each motor, rather than place separate restrictions in thesepassages but restrictions could be used at each slave valve. Since it ismost convenient to make all the lines about this same size, the lowerflow rate for upshift exhaust and feed is provided by separaterestrictions, all located at the slave valve ports. This is shown forall power shifts below.

In the above description, references to a direction of the valve on thedrawing as right or left is merely for convenience and it will beappreciated that the location and relative arrangement of the valves isnot important but that they perform the above described functions in anyposition except for the lockup cut-off valves and shuttle valves.

It will be appreciated that the invention may be used in the abovedescribed preferred embodiment and modifications thereof.

it is claimed:

1. In a transmission; input means; output means; multispeed gear meansconnecting said input and output means and having a plurality of fluidoperated drive devices including a main fluid operated forward driveestablishing device and a first, intermediate and high individual speedfluid operated forward drive establishing devices sequentially operativewhen said main forward drive device is established to establish first,intermediate and high, a series of increasing speed forward drives andtwo of said fluid operated drive devices including at least one of saidforward drive devices establishing an additional drive; a source offluid under pressure; shift valve means including a first and secondshift valve each having a supply port; said first shift valve operativein a downshift position for connecting its supply port to said firstspeed individual fluid operated speed drive establishing device andoperative in an upshift position for connecting the supply port of saidfirst shift valve to the supply port of said second shift valve; saidsecond shift valve operative in a downshift position for connecting itssupply port to establish said intermediate individual speed driveestablishing device and operative in an upshift position for connectingits supply port to establish said high drive establishing device;automatic control means operative in response to output speed forsequentially upshifting said first and second shift valves withincreasing output speed and selector valve means operative in anautomatic position for connecting said source to said forward drivedevice and said supply port of said first shift valve for establishingautomatic shifting between said first, intermediate and high forwarddrives and an additional drive position connecting said source to saidshift valve means and to one of said two drive devices for saidadditional drive for establishing said one drive device and conditioningsaid shift valve means for supplying fluid for the other of said twodrive devices for said additional drive, to establish said additionaldrive through said first shift valve only when placed in the downshiftedposition by said automatic control means.

2. The invention defined in claim 1 and said additional drive being areverse drive; said one drive device for said additional drive beingsaid high drive device and said selector valve means in said additionaldrive position connecting said source to said second shift valve toestablish said high drive device and said other drive device for saidadditional drive being said first drive device.

3. The invention defined in claim 1 and said additional drive being alow drive; said one drive device for said additional drive being saidmain forward drive device and said other drive device for saidadditional drive being a low drive device.

4. The invention defined in claim 1 and said additional drive being alow drive; said other drive device for said additional drive being a lowdrive device; said shift valve means including an additional shift valveand said first shift valve in said downshifted position connecting saidsource to said additional shift valve which selectively feeds said firstdrive device when said selector valve is in said automatic position andfeeds said low drive device when said selector valve is in saidadditional position.

5. The invention defined in claim 4 and governor controlled inhibitormeans connected to said additional shifi valve means to preventdownshift of said additional shift valve means above a predeterminedspeed, a torque converter having an output and lockup clutch in serieswith said multispeed gear means between said output and input means,governor shift means responsive to the speed of said torque converteroutput only above a higher predetermined speed to engage said lockupclutch to prevent lockup clutch engagement in said low ratio.

6. In a transmission; input means; output means; multispeed gear meansconnecting said input and output means and having a plurality of fiuidoperated drive devices including a fluid operated main forward driveestablishing device and a first, intermediate and high individual speedfluid operated forward drive establishing devices sequentially operativewhen said forward drive device is established to establish first,intermediate and high, a series of increasing speed forward drives andtwo of said fluid operated drive devices including at least one of saidforward drive devices operative for establishing an additional drive; asource of fluid under pressure; relay valve means including a first andsecond relay valve each having a supply port; said first relay valveoperative in a downshift position for connecting said source to saidfirst speed individual fluid operated speed drive establishing deviceand operative in an upshift position for connecting the supply port ofsaid first relay valve to the supply port of said second relay valve;said second relay valve operative in a downshift position for connectingits supply port to establish said intermediate individual speed driveestablishing device and operative in an upshift position for connectingits supply port to establish said high drive establishing device;governor means providing a governor signal; automatic shift valves foreach relay valve means each operativein response to said governor signalfor sequentially each providing a shift signal for upshifting said firstand second relay valves with increasing output speed and selector valvemeans operative in an automatic position for connecting said source tosaid main forward drive device and to said supply port of said firstrelay valve for establishing automatic shifting between said first,intermediate and high forward drives and an additional drive positionconnecting said source to said relay valve means and to one of said twodrive devices for said additional drive for establishing said one drivedevice and conditioning said relay valve means for supplying fluid forestablishing the other of said two drive devices for said additionaldrive to establish said additional drive through 28 said first relayvalve only when placed in the downshifted position by said automaticcontrol means.

7. The invention defined in claim 6 and said additional drive being areverse drive; said one drive device for said additional drive beingsaid high drive device and said selector valve means in said additionaldrive position for reverse drive connecting said source to said secondrelay valve to establish said high drive device and said other drivedevice for said additional drive being said first drive device.

8. The invention defined in claim 7 and said second relay whendownshifted having an exhaust connected to the high establishing device;said selector valve means in reverse drive position connecting saidsource to said exhaust connected by the downshifted second relay valveto the high establishing device and to the supply port of said firstrelay valve for establishing said first drive device only on downshiftof said first relay valve so reverse drive cannot be established abovethe speed for first drive.

9. The invention defined in claim 6 and said additional drive devicebeing a low drive device; a low relay valve in the connection betweensaid first relay valve normally in an upshift position providing aconnection to said first device and in a downshift position to said lowdevice; said selector valve means in said additional position connectingsaid source to said forward drive device and to said supply port of saidfirst relay valve means and said source to said low relay valve to moveit to downshift position to establish low only when said first relayvalve is downshifted.

10. In a transmission; input means; output means; multispeed gear meansconnecting said input and output means and having a plurality of fluidoperated drive establishing devices including a forward driveestablishing device and a first, second and third individual fluidoperated speed drive establishing devices sequentially operative whensaid forward drive device is established to establish a series ofincreasing speed forward drives; a source of fluid under pressure; adrive pressure line having priority means to delay fluid pressure flowtherethrough; first and second shift valves; automatic shift means tosequentially upshift said first and second shift valves with increasingoutput speed; said first shift valve operative in a downshift positionto provide a connection connecting said source to said first speedindividual drive device for establishing said first speed devicewhenever the output is stationary or coasting at speeds less than thespeed required to upshift said first shift valve and in an upshiftposition to connect said drive pressure line to a second of said shiftvalves; said second shift valve in a downshift position feeding saidsecond drive device and in an upshift position feeding said third drivedevice; manual selector valve means operative in a neutral positionconnecting said drive pressure line to exhaust to prevent establishmentof second and third speeds so said first speed device is onlyestablished when the output is stationary or coasting at speeds lessthan the speed required to upshift said first shift valve and anautomatic drive position to connect said source to said drive pressureline and to said forward drive device for engaging said forward drivedevice for completing the drive when the vehicle is stationary orcoasting at a speed less than the speed required to upshift said firstshift valve and for first en-

1. In a transmission; input means; output means; multispeed gear meansconnecting said input and output means and having a plurality of fluidoperated drive devices including a main fluid operated forward driveestablishing device and a first, intermediate and high individual speedfluid operated forward drive establishing devices sequentially operativewhen said main forward drive device is established to establish first,intermediate and high, a series of increasing speed forward drives andtwo of said fluid operated drive devices including at least one of saidforward drive devices establishing an additional drive; a source offluid under pressure; shift valve means including a first and secondshift valve each having a supply port; said first shift valve operativein a downshift position for connecting its supply port to said firstspeed individual fluid operated speed drive establishing device andoperative in an upshift position for connecting the supply port of saidfirst shift valve to the supply port of said second shift valve; saidsecond shift valve operative in a downshift position for connecting itssupply port to establish said intermediate individual speed driveestablishing device and operative in an upshift position for connectingits supply port to establish said high drive establishing device;automatic control means operative in response to output speed forsequentially upshifting said first and second shift valves withincreasing output speed and selector valve means operative in anautomatic position for connecting said source to said forward drivedevice and said supply port of said first shift valve for establishingautomatic shifting between said first, intermediate and high forwarddrives and an additional drive position connecting said source to saidshift valve means and to one of said two drive devices for saidadditional drive for establishing said one drive device and conditioningsaid shift valve means for supplying fluid for the other of said twodrive devices for said additional drive, to establish said additionaldrive through said first shift valve only when placed in the downshiftedposition by said automatic control means.
 2. The invention defined inclaim 1 and said additional drive being a reverse drive; said one drivedevice for said additional drive being said high drive device and saidselector valve means in said additional drive position connecting saidsource to said second shift valve to establish said high drive deviceand said other drive device for said additional drive being said firstdrive device.
 3. The invention defined in claim 1 and said additionaldrive being a low drive; said one drive device for said additional drivebeing said main forward drive device and said other drive device forsaid additional drive being a low drive device.
 4. The invention definedin claim 1 and said additional drive being a low drive; said other drivedevice for said additional drive being a low drive device; said shiftvalve means including an additional shifT valve and said first shiftvalve in said downshifted position connecting said source to saidadditional shift valve which selectively feeds said first drive devicewhen said selector valve is in said automatic position and feeds saidlow drive device when said selector valve is in said additionalposition.
 5. The invention defined in claim 4 and governor controlledinhibitor means connected to said additional shift valve means toprevent downshift of said additional shift valve means above apredetermined speed, a torque converter having an output and lockupclutch in series with said multispeed gear means between said output andinput means, governor shift means responsive to the speed of said torqueconverter output only above a higher predetermined speed to engage saidlockup clutch to prevent lockup clutch engagement in said low ratio. 6.In a transmission; input means; output means; multispeed gear meansconnecting said input and output means and having a plurality of fluidoperated drive devices including a fluid operated main forward driveestablishing device and a first, intermediate and high individual speedfluid operated forward drive establishing devices sequentially operativewhen said forward drive device is established to establish first,intermediate and high, a series of increasing speed forward drives andtwo of said fluid operated drive devices including at least one of saidforward drive devices operative for establishing an additional drive; asource of fluid under pressure; relay valve means including a first andsecond relay valve each having a supply port; said first relay valveoperative in a downshift position for connecting said source to saidfirst speed individual fluid operated speed drive establishing deviceand operative in an upshift position for connecting the supply port ofsaid first relay valve to the supply port of said second relay valve;said second relay valve operative in a downshift position for connectingits supply port to establish said intermediate individual speed driveestablishing device and operative in an upshift position for connectingits supply port to establish said high drive establishing device;governor means providing a governor signal; automatic shift valves foreach relay valve means each operative in response to said governorsignal for sequentially each providing a shift signal for upshiftingsaid first and second relay valves with increasing output speed andselector valve means operative in an automatic position for connectingsaid source to said main forward drive device and to said supply port ofsaid first relay valve for establishing automatic shifting between saidfirst, intermediate and high forward drives and an additional driveposition connecting said source to said relay valve means and to one ofsaid two drive devices for said additional drive for establishing saidone drive device and conditioning said relay valve means for supplyingfluid for establishing the other of said two drive devices for saidadditional drive to establish said additional drive through said firstrelay valve only when placed in the downshifted position by saidautomatic control means.
 7. The invention defined in claim 6 and saidadditional drive being a reverse drive; said one drive device for saidadditional drive being said high drive device and said selector valvemeans in said additional drive position for reverse drive connectingsaid source to said second relay valve to establish said high drivedevice and said other drive device for said additional drive being saidfirst drive device.
 8. The invention defined in claim 7 and said secondrelay when downshifted having an exhaust connected to the highestablishing device; said selector valve means in reverse drive positionconnecting said source to said exhaust connected by the downshiftedsecond relay valve to the high establishing device and to the supplyport of said first relay valve for establishing said first drive deviceonly on downshift of said firsT relay valve so reverse drive cannot beestablished above the speed for first drive.
 9. The invention defined inclaim 6 and said additional drive device being a low drive device; a lowrelay valve in the connection between said first relay valve normally inan upshift position providing a connection to said first device and in adownshift position to said low device; said selector valve means in saidadditional position connecting said source to said forward drive deviceand to said supply port of said first relay valve means and said sourceto said low relay valve to move it to downshift position to establishlow only when said first relay valve is downshifted.
 10. In atransmission; input means; output means; multispeed gear meansconnecting said input and output means and having a plurality of fluidoperated drive establishing devices including a forward driveestablishing device and a first, second and third individual fluidoperated speed drive establishing devices sequentially operative whensaid forward drive device is established to establish a series ofincreasing speed forward drives; a source of fluid under pressure; adrive pressure line having priority means to delay fluid pressure flowtherethrough; first and second shift valves; automatic shift means tosequentially upshift said first and second shift valves with increasingoutput speed; said first shift valve operative in a downshift positionto provide a connection connecting said source to said first speedindividual drive device for establishing said first speed devicewhenever the output is stationary or coasting at speeds less than thespeed required to upshift said first shift valve and in an upshiftposition to connect said drive pressure line to a second of said shiftvalves; said second shift valve in a downshift position feeding saidsecond drive device and in an upshift position feeding said third drivedevice; manual selector valve means operative in a neutral positionconnecting said drive pressure line to exhaust to prevent establishmentof second and third speeds so said first speed device is onlyestablished when the output is stationary or coasting at speeds lessthan the speed required to upshift said first shift valve and anautomatic drive position to connect said source to said drive pressureline and to said forward drive device for engaging said forward drivedevice for completing the drive when the vehicle is stationary orcoasting at a speed less than the speed required to upshift said firstshift valve and for first engaging said forward drive device and thenengaging the one of second or third drive device when coasting at highspeeds in accordance with the automatic shift means control of saidsecond shift valve.
 11. The invention defined in claim 10 and saidpriority means being a pressure responsive valve permitting flowtherethrough in said drive pressure line when the upstream pressure issufficient for proper operation of said individual fluid operateddevices.
 12. The invention defined in claim 10 and said multispeed gearmeans being operative on the establishment of said first and third speeddrive establishing devices and the disestablishment of said forwarddrive device to establish reverse drive; said selector valve means beingoperative in a reverse position to exhaust said drive pressure line andconnect said source pressure to said second shift valve to establishsaid third speed drive establishing device and reverse being establishedwhen said first shift valve automatically downshifts to establish saidfluid operated device.
 13. The invention defined in claim 11 and saidmultispeed gear means being operative on the establishment of saidforward fluid operated device and an additional low speed fluid operateddevice to establish an additional low speed; an additional shift valvein said connection between said first shift valve and said first speeddevice having an upshift position providing a connection to said firstspeed device to establish first sPeed and a downshift position providinga connection to said lower speed device to establish said lower speedand said selector valve having a low position connecting said source tosaid forward drive device and acting on said additional low shift valveto downshift it.
 14. The invention defined in claim 13 and governormeans to prevent downshift of said additional low speed shift valve bysaid selector valve above a predetermined speed.
 15. In a transmission;input means; output means; multispeed gear means connecting said inputand output means and having a fluid operated forward drive establishingdevice and a plurality of individual fluid operated first through fourthspeed drive establishing devices sequentially operative when saidforward drive device is established to establish a series of increasingspeed forward drives; a source of fluid under pressure; a plurality ofshift valves including first, second and third shift valves each havinga supply port; said first shift valve selectively connecting a firstsupply port to said first and second individual drive establishingdevices when downshifted and upshifted respectively; said second shiftvalve selectively connecting said source to the supply port of saidfirst shift valve and its second supply port to the supply port of saidthird shift valve when downshifted and upshifted respectively; saidthird shift valve connecting said third supply port selectively to athird and a fourth individual drive establishing device when downshiftedand upshifted respectively; automatic control means responsive to thespeed of said output means and torque demand operative to sequentiallyupshift and downshift said second and third shift valves and selectorvalve means operative in a forward automatic range position to connectsaid source to said forward drive establishing device and said supplyport of said second shift valve and position said first shift valve forsecond drive and permitting automatic shifting of said second and thirdshift valves by said automatic control means and operative in a firstdrive position to discontinue the supply from said source to said supplyport of said second shift valve to prevent the establishment of saidthird and fourth speed devices and position said first shift valve inthe downshift position to establish said first drive establishingdevice.
 16. The invention defined in claim 15 and said multispeed gearmeans being operative on the establishment of said second and fourthspeed drive establishing devices and the disestablishment of saidforward drive establishing device to establish reverse drive; saidmanual selector valve means being movable to a reverse positionexhausting said drive pressure line, connecting main line pressure tosaid third shift valve to establish said fourth drive establishingdevice and upshifting said first shift valve for operation on theautomatic downshift of said second shift valve to directly connect saidsource to said first shift valve which in the upshift positionestablishes said second speed device which with the established fourthspeed device provides reverse drive.
 17. The invention defined in claim16 and said automatic control means including an output governorproviding an output governor signal, a torque demand means providing asignal proportional to torque demand and automatic shift valve means foreach of said second and third shift valves operative in response to saidgovernor signal and said torque demand signal to provide first andsecond upshift signal at low and high ranges of speeds increasing withtorque demand and a discontinuance of said signal at low and high rangesof speeds increasing at a faster rate with torque demand and said shiftvalves being relay shift valves and said second and third relay valvesbeing respectively responsive to said first and second upshift signals.18. The invention defined in claim 16 and a hold pressure regulatorvalve providing a hold signal pressure and said selector valveconnectIng said hold signal pressure to said first shift valve todownshift said first shift valve in said first drive position and havinga second automatic range connecting said hold signal pressure to saidautomatic control means to provide upshifts of at least one shift valveat higher speeds.
 19. In a transmission; input means; output means;multispeed gear means having low, first intermediate, secondintermediate and high speed drive establishing devices connecting saidinput and output means; a source of fluid under pressure; a low,intermediate and high shift valve means each having an inlet port means,a low and a high outlet port and exhaust port means and biasing meansbiasing said shift valve means to low position connecting said inletport means to said low outlet port and said high outlet port to saidexhaust port means and having fluid pressure responsive means to shiftsaid shift valve means to high position connecting said inlet port meansto said high outlet port and said low outlet port to said exhaust portmeans; first passage means connecting said source to said inlet portmeans of said low shift valve means; second passage means connectingsaid low outlet port means of said low shift valve means to said lowspeed device; third passage means connecting said high outlet port ofsaid low shift valve means to said inlet port means of said intermediateshift valve means; fourth passage means connecting said low outlet portof said intermediate shift valve means to said first intermediate speeddevice; fifth passage means connecting said high outlet port of saidintermediate shift valve means to said inlet port means of said highshift valve means; sixth passage means connecting said low outlet portof said high shift valve means to said second intermediate speed deviceand seventh passage means connecting said high outlet port of said highshift valve means to said high speed device.
 20. The invention definedin claim 19 and said inlet port means including a high inlet portconnecting said high outlet port when the shift valve means is in highposition and a low inlet port connecting to said low outlet port whenthe shift valve means is in low position and each high inlet port havingmore restriction.
 21. The invention defined in claim 20 and said lowinlet port of said high shift valve means having a restriction.
 22. Theinvention defined in claim 19 and said exhaust port means including ahigh exhaust port connected to said high outlet port when the shiftvalve means is in low position and a low exhaust port connected to saidlow outlet port when the shift valve means is in high position and saidlow exhaust port being more restricted.
 23. The invention defined inclaim 20 and said exhaust port means including a high exhaust portconnected to said high outlet port when the shift valve means is in lowposition and a low exhaust port connected to said low outlet port whenthe shift valve means is in high position and said low exhaust portbeing more restricted.
 24. In a transmission; input means; output means;multispeed gear means connecting said input and output means and havinga fluid actuated forward drive establishing device actuated in allforward drives and a plurality of fluid actuated individual speed drivedevices individually actuated to provide when the forward drive deviceis actuated a series of forward speed drives; a source of fluid under aregulated pressure; governor means connected to said source andproviding a governor pressure proportional to transmission speed;automatic shift valve means responsive to said governor pressure tosequentially upshift for sequentially engaging said individual fluidactuated forward speed drive devices; priority valve means operative inresponse to normal pressure to permit flow of the normal pressure and inresponse to less than normal pressure to reduce flow; and manual controlmeans connecting said source directly to said fluid actuated forwarddrive device and through said priority valve meAns to said automaticshift valve means so the source pressure is maintained at said normalpressure in order to maintain proper system pressures.
 25. The inventiondefined in claim 24 and an additional fluid actuated individual speeddrive device; an additional shift valve operative in one position tosupply said additional speed drive device and in another position tosupply one of said individual speed drive devices; said automatic shiftvalve means in one position being connected through said additionalshift valve means to supply fluid from said source to selectivelyactuate said additional fluid actuated device and said one of saidindividual speed drive devices and said manual control means connectingsaid source pressure to said additional shift valve to select saidadditional and said one fluid actuated speed drive devices.
 26. In atransmission; input means; output means; multispeed gear meansconnecting said input and output means and having in series a first,second and third increasing speed drive establishing devices; a sourceof fluid under pressure; first and second shift valve means each havinga first and a second inlet port, a first and a second outlet port andexhaust port means; said first shift valve means having both inlet portsconnected to said source and said first outlet port connected to saidfirst speed drive device and operative in a downshift position toconnect its first inlet port to its first outlet port and in an upshiftposition to connect its second inlet port to its second outlet port, andsaid second shift valve means having both of its inlet ports connectedto said second outlet port of said first shift valve means, its firstoutlet port connected to said second speed drive device and its secondoutlet port connected to said third speed drive device and beingoperative in a downshift position to connect its first inlet port to itsfirst outlet port connected to said second speed drive device and in anupshift position to connect its second inlet port to its second outletport connected to said third speed drive device, said first inlet portof said first shift valve means having a flow capacity controlling onlythe flow for said first speed drive device; said first inlet port ofsaid second shift valve having a flow capacity controlling only the flowfor said second speed drive device and said second inlet port of saidsecond shift valve having a flow capacity controlling only the flow forsaid third speed drive device.
 27. The invention defined in claim 26 andsaid first shift valve means having exhaust port means including a firstexhaust port for controlling the flow capacity of only the connection ofsaid first speed drive device to exhaust after moving from the downshiftposition to the upshift position.
 28. The invention defined in claim 26and said second shift valve means having exhaust port means including afirst exhaust port for controlling the flow capacity of only theconnection of said second speed drive device to exhaust after movingfrom the downshift position to the upshift position.
 29. The inventiondefined in claim 26 and said second shift valve means having exhaustport means including a second exhaust port controlling the flow capacityof only the connection of said third speed drive device to exhaust aftermoving from the upshift position to the downshift position.
 30. In atransmission; input means; output means; multispeed gear meansconnecting said input means and output means and having in a consecutivespeed drive series first, second and third increasing speed driveestablishing devices; a source of fluid under pressure; shift valvemeans selectively connecting said source to said first, second and thirddevices having feed passages for feed flow for selectively establishingthe respective first, second and third speed device, a first and asecond flow controlling upshift exhaust passage portions, each only forexhaust flow for disestablishing respectively said first and seconddevice duriNg upshifts from first to second and second to third speedsand a second and a third flow controlling downshift exhaust passageportions, each only for exhaust flow for disestablishing respectivelysaid second and third device during downshifts from third to second andsecond to first speeds; each upshift and downshift flow controllingexhaust passage portion being independent of the other flow controllingupshift and downshift exhaust passage portions.
 31. The inventiondefined in claim 30 and each of said flow controlling upshift exhaustpassage portions being more restricted than the flow controllingdownshift exhaust passage portion for the same speed device providing aslower disestablishment rate on upshift than on downshift.
 32. Theinvention defined in claim 30 and said flow controlling upshift anddownshift exhaust passage portions being independent of said feedpassages.
 33. In a transmission; input means; output means; multispeedgear means connecting said input means and output means and having in aconsecutive speed drive series first, second and third increasing speeddrive establishing devices; a source of fluid under pressure; shiftvalve means selectively connecting said source to said first, second andthird devices having a first, a second and a third flow controlling feedpassage portions, each only for feed flow to and for establishing therespective first, second and third device for providing a controlledestablishing rate for each device independent of the establishing rateof the other devices, a first and a second flow controlling upshiftexhaust passage portions, each only for exhaust flow for disestablishingrespectively said first and second device during upshifts from first tosecond and second to third speeds and a second and a third flowcontrolling downshift exhaust passage portions, each only for exhaustflow for disestablishing respectively said second and third deviceduring downshifts from third to second and second to first speeds; eachupshift and downshift flow controlling exhaust passage portion beingindependent of the other flow controlling upshift and downshift exhaustpassage portions and said flow controlling feed passage portions, eachof said flow controlling upshift exhaust passage portions being morerestricted than the flow controlling downshift exhaust passage portionfor the same speed device providing a slower disestablishment rate onupshift than on downshift and said flow controlling feed passageportions being independent of said flow controlling upshift anddownshift exhaust passage portions.
 34. The invention defined in claim33 and said first, second and third flow controlling feed passageportions being more restricted than said flow controlling downshiftexhaust passage portions.
 35. In a transmission; input means; outputmeans; multispeed gear means connecting said input and output means andhaving in consecutive series a first, second and third increasing speeddrive establishing devices; a source of fluid under pressure; first andsecond shift valve means each having inlet passage means, a first and asecond outlet passage and exhaust passage means; said first shift valvemeans having its inlet passage means connected to said source and itsfirst outlet passage connected to said first speed drive device andoperative in a downshift position to connect its inlet passage means toits first outlet passage to feed and establish said first speed deviceand connect its second outlet passage to its exhaust passage means andin an upshift position to connect its inlet passage means for feed flowto its second outlet passage and its first outlet passage to its exhaustpassage means to exhaust and disestablish said first speed device, andsaid second shift valve means having inlet passage means having a firstrestricted inlet passage with a bypass blocking feed flow and permittingreturn flow and a second restricted inlet passage, both connected tosaid second outlet passage of said first shift valve means, its firstoutlet passage connected to said second speed drive device and itssecond outlet passage connected to said third speed drive device andbeing operative in a downshift position to connect its first restrictedinlet passage to its first outlet passage connected, when said firstshift valve means is upshifted for feed to and for establishing saidsecond speed drive device and, when said first shift valve means isdownshifted for exhausting through its first restricted inlet passageand its bypass to the second outlet passage and exhaust passage means ofsaid first shift valve means and connecting said third speed drivedevice to its exhaust passage means and in an upshift position toconnect its second restricted inlet passage to its second outlet passagefor feed to said third speed drive device and connecting said secondspeed drive device by its first outlet passage to its exhaust passagemeans and said first inlet passage of said second shift valve having aflow capacity controlling only the feed flow for said second speed drivedevice and said second inlet passage of said second shift valve having aflow capacity controlling only the flow for said third speed drivedevice.
 36. In a transmission; input means; output means; multispeedgear means connecting said input and output means and having inconsecutive series a first, second and third increasing speed driveestablishing devices; a source of fluid under pressure; first and secondshift valve means each having first and second inlet passages, outletpassages and exhaust flow control passages; said first shift valve meanshaving its first and second inlet passages connected to said source andits first outlet passage connected to said first speed drive device andoperative in a downshift position to connect its first inlet passage,which has a flow control portion only for first speed establishment, toits first outlet passage to feed and establish said first speed deviceand connect its second outlet passage to its second exhaust flow controlpassage, to control only second speed disengaging exhaust on a secondfirst shift, and in an upshift position to connect its second inletpassage for feed flow to its second outlet passage and its first outletpassage to its first exhaust flow control passage to control only firstspeed disengaging exhaust on a first second shift; and said second shiftvalve means having its first and second inlet passages, both connectedto said second outlet passage of said first shift valve means, havingrespectively first and second flow control portions only for second andthird speed establishment, said first flow control portion having abypass blocking feed flow and permitting return flow, its first outletpassage connected to said second speed drive device and its secondoutlet passage connected to said third speed drive device and beingoperative in a downshift position to connect its second outlet to itssecond exhaust flow control passage to control only third sped exhauston a three two shift, its first inlet passage, when the first shiftvalve means is upshifted, for feed to its first outlet passage for feedto establish said second speed drive device and, when said first shiftvalve means is downshifted for exhausting said second speed devicethrough said bypass and first inlet passage of said second shift valvemeans to the second outlet and second exhaust flow control passage, ofsaid first shift valve means to control only second speed exhaust on asecond first shift, and in an upshift position to connect its secondinlet passage to its second outlet passage for feed to said third speeddrive device and connecting said second speed drive device by its firstoutlet passage to its first exhaust flow control passage only for secondspeed exhaust on a two three shift, the first inlet passage flow controlportions of said first and second shift valve means and the second inletpassage flow control portion of said second shift valve respectivelycontrolling only the feed Flow for establishing said first, second andthird speed drives, said first and second exhaust flow control passagesof said first shift valve means controlling respectively only exhaustflow for disestablishing said first speed drive on a first to secondshift and for disestablishing second speed drive on a two one shift, thefirst and second exhaust flow control passages of said second shiftvalve means controlling respectively only exhaust flow fordisestablishing said second speed drive on a second to third shift andfor disestablishing said third speed drive on a three two shift.